This invention relates to the lowering of blood cholesterol levels in mammals and humans by administering a cholesterol lowering effective amount of granulocyte-macrophage colony stimulating factor (GM-CSF).
GM-CSF is a lymphokine (stimulator of the immune system) that exhibits a broad spectrum of immune cell stimulation as described in Burgess and Metcalf, Blood, 56: 947 (1980) and Metcalf, Blood, 67: 257 (1986). GM-CSF has been shown to increase the leukocyte count in patients with acquired immunodeficiency syndrome [Brandt et al., N. Engl. J. Med., 318: 869 (1988)] and people suffering from chemotherapy-induced myelosuppression [Antman et al., New Engl. J. Med., 319: 593 (1988)] and it has been suggested that various colony stimulating factors alone or in combination with erythropoietin and/or an antiviral agent and/or interleukin-2 (IL-2) may be useful for the treatment of patients suffering from AIDS-type disease (PCT Application No. 87/03204).
Although GM-CSF was identified because of its ability to stimulate proliferation of hematopoietic precursor cells, it is also able to stimulate a number of functional aspects of mature granulocytes and macrophages. These effects include synthesis of biologically active molecules such as prostaglandin E [Hancock et al., J. Immunol., 140: 3021 (1988) and Kurland et al., Proc. Natl. Acad. Sci. USA, 76: 2326 (1979)]; increased phagocytic activity [Weisbart et al., Nature, 332: 647 (1988)]; expression and/or affinity of various membrane markers such as the IL-2 receptor [Hancock et al., J. Immunol., 140: 3021 (1988)] and the bacterial product formylmethionylleucylphenylalanine receptor on neutrophils, which receptors elicit the production of superoxide anions [Atkinson et al., Immunology, 64: 519 (1988)]; and the regulation of enzyme activity such as the stimulation of guanylate cyclase and the inhibition of adenylate cyclase [Coffey et al., J. Immunol., 140: 2695 (1988)].